Question:I keep shearing magneto keys!
Answer:Montesa uses a very small key, good thing! when it shears it usually
leaves half in the shaft and half in the flywheel, usually not messing up the shaft.
The fix is to lap the flywheel to the shaft with valve lapping compound. Compound usually
comes in two containers, one medium and one fine. Just paste the compound on the shaft and
rotate the flywheel on the shaft (without the key installed, of course!)working up to the fine paste.
Be sure to clean everything off between lappings! This will remove any high spots on the shaft and
flywheel and help to keep it from turning. If it's a real problem, lap in the shaft, heat the flywheel in the
oven, and use red locktite, torque flwheel nut to 72 ft lbs. That should keep it in place!
Question: How do I remove the primary gear?
Answer: Most pullers are not heavy duty enough to handle this job!
the best puller to use, is a automotive pittman arm puller, these can even
be rented, you must make sure that the arms get as much contact on the gear
as possible. An impact wrench, and the application of heat on the gear, may
be needed.
Question: I removed the head nuts, and the barrel
will not come off!
Answer: Later model barrels are held down by four 7mm allen nuts.
This is an uncommon size, but SnapOn tools make a long allen wrench with
a 3/8 socket on the end that works perfect. A good metric supply store should
have this size. In many cases, use an impact hammer to loosen, to keep from
ruining the allen nut. If you strip the allen nut, you will have to drill it out
and the cylinder stud will be ruined
Question: The damn magneto nut won't come
loose!
Answer:The magneto nut goes clockwise to loosen, same as the countershaft
sprocket nut.
Question: I checked the ring gap on my V.R. engine,
and it's over 80 thousandth's! what gives?
Answer: The rings in the V.R. are designed to butt up against the
locater pin, when measuring, you must take into account the thickness of
this pin.
Question: The collar that holds the pipe on keeps
coming loose!
Answer: Coat the threads with anti-seize compound, tighten with the
correct spanner and safety wire the collar to the hole that is in the lowest
fin on the barrel. Some people fit a spring from the collar to the barrel
for extra protection.
Question: Do I have to split the cases to change the
crankseals?
Answer: No!, The crankseals are accessable from the outside, removel
of the magneto and the primary gear is all that's required.
Question: My bike sometimes pops out of gear, is there
anything that can be done?
Answer: Remove the 17mm bolt in the rear of the case, on the sprocket
side. There will be a detent plunger and a spring. Install a small ball bearing
behind the spring and reinstall. Shifting will be slightly harder, but will
be more positive.
Question: Oil blows out the breather hole in the rear
of the case making a mess!
Answer: Block the hole with a dab of epoxy, and vent the filler cap
for the gearbox with fuel line, running the line up under the fuel tank.
Question: My ignition points are always pitted, and
the condensor keeps failing.
Answer: You could not mount a condensor in a worst spot! Extreme heat
and vibration will make them fail in no time! Disable the stock unit on the
backing plate. Purchase any good automotive condensor with a ground wire.
Mount the new unit under the tank or in the open (I use a small hose clamp
on the frame backbone) run the ground wire to the coil mounting bolt. Splice
the condensor's main wire into the hot wire coming out of the coil. Thats
it, no more burned points!
Question: When should I change the primary
chain?
Answer: Trick question! Montesa does not use primary chains.
Question: My manual for the Cappra 250 GP says to
set the timing at 6mm. BTDC, it kicks back hard, and is hard to
start.
Answer: This is wrong! timing should be set at no more than 4mm.
BTDC
Question: The clutch on my Cota drags, what can I
do?
Answer: This has always been a problem up until 1984. Check for warped
clutch plates, spring height, use a modern transmission oil.
Hot Tip!
If you repaint or powdercoat your frame, of course you always remove the coating from the coil bracket for a good ground. But, remember to remove the coating from at least one of the motor mounts to ensure a good ground for the engine to the frame. Don't do this, and you will lose your mind trying to figure out what wrong with your ignition or carb.